Current light emitting diode (LED) headlamp designs use a projector system to build the high beam hotspot and imaged masks or source shapes to generate the sharp cutoff in the low beam pattern. This is a costly, complex and inefficient solution. Previous designs involved an optical element that produced a wide beam pattern with tall thin optical elements eliminating much of the complexities associated with prior art designs, and providing improved efficiency over projector systems. However, the pattern produced using this design was very wide and smooth, providing insufficient intensity in the center of the pattern; therefore, a projector system was still needed to produce the high beam and low beam hotspots required to achieve a complete beam pattern.
Additionally, when a light source is used to provide light for an input surface of an optical element, the light from the light source often does not provide light for the entire area of the input surface. This will often result in a “banding effect,” where waves of alternating light and dark areas are seen in the resulting beam pattern.
Another difficulty which arises in the production of optics is that there are certain requirements which must be met with regard to acceptable levels of glare produced by a headlamp directed towards a driver's eyes when two vehicles are approaching each other from opposite directions. Headlamps need to accommodate for this glare, and must not produce light in certain glare test points, which represent the oncoming driver's eye location.
Accordingly, there exists a need for a lighting device which is able to produce the desired beam pattern, while overcoming the aforementioned problems.